1. Field of the Invention
The present invention is directed generally to a lightweight, absorbent, disposable pad, and particularly to a lightweight, absorbent, disposable pad that entraps particles, retains liquid, and eliminates odors. The pad can be used in a variety of ways in households, automobiles, and industry.
The present invention relates to the field of super absorbent compositions in combination with high loft non-wovens used in pads to entrap particles and contain liquids from sources such as people and animals, industrial sites, hospitals, dish racks, flower pots, hazardous material containers and the like. The absorbent compositions are also capable of controlling odors through water evaporation and concomitant reduction of bacterial action. The sorbent compositions are composed of silica aerogels or super absorbent polymers integrated with fibrous materials and assembled in layers into a pad or covering material, which can prevent exposure to users of the absorbent material.
2. Description of the Related Art
Many pet, household, and commercial items and products require the need for a pad that traps and captures stray particles, excessive liquids, or both, preventing them from soiling other areas. For example, many cat litter boxes cause litter particles to escape onto nearby floor surfaces. Some commercially available mats and artificial turf have been sold, which retail for $5.00 to $10.00, and are designed to trap litter. These mats are heavy and expensive. Artificial turf is avoided by many animals due to the sharp, crisp, stiff feel of the turf on their paws. Also, many pet food dishes for dogs and cats do not allow for absorbing spillage of liquids, drinking water, and soft and hard particles of food from these surfaces.
Many mats commercially sold for use around the home, such as dish rack drain mats, and entrance mats can be vastly improved in design, disposability, cleanliness, cost, cleaning ability, absorbency, and odor prevention by using the present invention as a substitute. There are multiple household needs that can be met by the present invention. For example, people with dirty shoes track soil, moisture, and odors into the home, workplace, and public buildings, and refrigerators need a means for absorbing odors and liquids. Additionally, many bathrooms contain soap dishes and bathtub mats that try to contain and absorb excessive soap, drippings, and moisture. Also, most garbage pails or kitchen pails have a need for absorbing leakage that causes odors, and many potted plants overflow when watered or leak soil outside of the pot. In the garage and commercial work place many items can produce dust or shavings from wood, metal, plastics, cardboard, etc. that escape onto and soil other surfaces. In the case of photocopy machines, printers, and other devices that use carbon particle cartridges, much of the dust falls to the floor and other surfaces when cleaning or replacing these items.
Absorbent materials for retaining and confining liquids are well known. Many naturally found materials are capable of confining liquids. Porous, absorbent clays and sands are commonly used in animal litters. Fibrous materials such as cotton and wood pulp are woven into absorbent pads and towels. Even straw is used for animal bedding and absorption or dispersion of wastes. Most of these materials have limitations on their absorbency and are incapable of controlling odors or capturing a variety of numerous heavy or fine particles efficiently.
Absorbent pads are conventionally used for a variety of commercial and industrial purposes. Such pads often are comprised of a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent layer containing a water absorbent resin and a fibrous material provided between the top and back sheets for absorbing and retaining a liquid. Such a pad for use with an animal litter box is described in U.S. Pat. No. 4,774,907 to Yananton. This pad is an improvement in rip-proof non-woven screens for use in combination with a sorbent padding, a liquid impermeable liner, a litter container and litter.
Many different types of media have been used as animal litters for disposing of liquid and solid waste. Among the more popular are clays, wood chip, cedar, alfalfa, corncob, newspaper, and the clumping clay based cat litters that contain silica. Certain litters contain 100% silica crystals. As silica is the main component in sand, rock, and mineral ores, its presence in cat litter is a possible health threat. Silica dust, if inhaled over time, can cause health problems. Silicosis is a lung disease caused by such a problem. Lung cancer and emphysema may also be due to inhalation of silica. As many animal litter boxes are confined within the household, the effects on animal owners and other household members exposed while changing, maintaining, and cleaning these are not known, but common sense dictates that exposure preferably be minimized.
Respiration problems are not the only hazard to consider when keeping an indoor litter box filled with silica crystals or clumping litters. All cats clean their fur and paws and may ingest the silica crystals. Humans, especially toddlers and young children, may be exposed to silica when they have wet hands. Clumping litters and silica crystal litters can cause extreme problems if ingested due to their moisture retaining ability.
Silica crystal litters, in particular, will immediately adhere to a wet surface, be it a paw, hand, mouth, tongue, eyes, or nasal membranes. Fine silica dust can cause extreme irritation to any exposed body parts, as mentioned, and larger silica particles can cause disruption of sensitive mucous membranes on immediate contact due to the extreme attraction of the dry silica to a moist surface.
Several products are on the market that put the pet and pet owners in direct contact with silica particles used as cat box filler. These silica particles contain silica dust, which fracture into smaller particles when wet, and can be tracked into the floor by the cat when exiting the litter box. Small sprays of silica dust can be seen coming from silica litters when wet.
Silica gel remains the highest capacity adsorbent available today. It is synthetically manufactured from sodium silicate. Each small granule is composed of a vast network of inter-connecting microscopic pores, which attract and hold moisture by a phenomenon known as physical adsorption and capillary condensation. Hydro sorbent silica gel is inert and has an immense area of internal adsorption.
The dehydration of animal urine exposed to silica gel or crystals is different from the dehydration that occurs by wicking and evaporation in a three-layered pad, as described in the '907 patent. Urine entering a pad that consists of long and short fiber of wood pulp, or super absorbent polymers, quickly wicks away moisture, which evaporates, and prevents bacterial action. Silica gel or crystals dehydrate the animal urine by adsorbing the urine into the silica particles where it becomes bound up and remains entrapped.
Whereas many pet owners may prefer the longevity and anti-odor characteristics of the silica products, they fear direct contact with these products because of the unknown health hazards that may result due to direct or indirect contact with the silica particles or dust. Use of these silica products for other household or industrial purposes places the user at risk and an alternative is needed. For example, silica particles from a litter box can escape and be tracked onto the floor, needlessly exposing members of the household to a potential health hazard. There is a need for containment of such silica particles whether they are being used in litter boxes, under dish racks, flower pots, potted plants, and for wet footwear, etc.
The pads of the present invention can be manufactured easily and inexpensively, are durable, and can be treated with or contain additional odor-counteractive agents, baking soda, silica particles, super absorbent polymers, or combinations of all of the above, as well as oils and anti-bacterials of all natures to enhance the absorbency of particle-entrapping nature of the pad.
Pads can be manufactured as strict particle entrapping, two-layered pads, or absorbent liquid particle trapping three-layer pads.